High seed yarn knitting apparatus

ABSTRACT

A knitting machine is described in which the elastic thread packages ( 26 ) are mounted in a stationary position away from the knitting head ( 22 ). This results in reducing the revolving mass and the space necessary to accommodate the revolving mass. Furthermore, the commencement of wind on the package ( 26 ) can be left as a tail which is knotted to the free end of a second package thus permitting the machine to run continuously without stopping to change packages. A plurality of like knitting heads ( 22 ) is mounted in relatively close proximity in a single knitting head frame ( 24 ) in such a manner that chain stitches are fed from a power driven warp beam ( 12, 16, 20 ). Each knitting head includes yarn positioning apparatus in which yarn ( 12 ) fed to each needle ( 30 ) of the knitting head ( 22 ) is moved under tension with minimal friction to a position where the needle ( 30 ) traps the yarn ( 12 ) on its downward stroke. Embodiments of the invention are described.

The prevent invention relates to apparatus for producing tubular fabricsconsisting of a number of separate chain stitches connected by an inlaidthread typically, elastic or similar yarn. In particular, the inventionrelates to a high speed yarn knitting apparatus for knitting netting forcovering food products, and in particular meat.

High speed yarn knitting apparatus should satisfy a number of desirablecriteria in addition to being reliable, fast and relatively inexpensive.It should permit the fabric to be continuously knitted and shouldrequire a minimal amount of space and be relatively lightweight. Thesupplies of yarn should be readily changed or added to withoutinterrupting the operation of the machine and a counterweight should notbe required to avoid imbalance at high speed. The high speed knittingapparatus should have yarn positioning apparatus which uses a minimalnumber of moving parts and wear and tear of knitting elements and yarnshould also be minimised. Higher tensions of yarn should be obtainableso that knitting speeds can be increased. The apparatus should alsominimise the splitting of yarn and the dropping of stitches.

Prior art knitting machines are of two general types. The first typeconsists of a machine which can make several rolls at a single timeusing a reciprocal movement. However, this machine is large and thereciprocal movement is very slow, thus limiting the amount of rolls ofknitted fabric which can be produced in a certain time. The second typeof machine uses a circular movement, however, this produces only asingle roll at a time and the size of the yarn package limits the amountof continuous netting which can be made without stopping. The yarnpackage is mounted to rotate with the cambox which means that the speedof rotation and hence knitting is limited. Also, when the weft packageis empty the machine must be stopped, reset and retensioned before itcan then operate. This takes time and the overall speed of the machineis relatively slow. In addition, because the package rotates, acounterweight is required for balance, which is heavy, and also requiresspace within the machine which results in the overall machine taking upa relatively large area.

Existing circular knitting machines which are also designed to make achain stitch structure use one of two generally accepted methods ofsupplying yarn to the needles of the knitting head. One method usesrotating or reciprocating guides which wrap the yarn around the needles.The elastic or other weft yarn is fed from the outside and is laidbetween the needles from the outside. This requires the weft yarnpackage to rotate with the cam box. In another method, stationary guidesare present and rely on being struck by the needles so as to deflect theneedles behind the yarn. The yarn is then caught by the open hook of theneedle as the needle descends. Again, the weft yarn package revolveswith the cam box.

These existing methods have a number of problems. The former method usesreciprocating guides requiring a machine which is relatively complicatedand uses a considerable number of moving parts. In the second method, asthe needles strike the guides there is considerable wear and tear onboth the needles and the guides. This can cause splitting of the yarnand dropping of stitches as well as broken knitting elements.

An object of the present invention is to provide an improved knittingapparatus and yarn tensioning apparatus which obviates or mitigates theaforesaid disadvantages. This is achieved by providing a high speedknitting apparatus in which the elastic thread packages are mounted in astationary position away from the knitting head and the yarn is fed fromthe exterior to the inside of each knitting head. Yarn is laid downoutside each needle as the needle rises but falls behind the needle asthe stitch is made allowing a stationary package. This results inreducing the revolving mass and the space necessary to accommodate therevolving mass. Furthermore, since the weft package is stationary, thecommencement of wind on the package can be left as a tail which isknotted to the free end of a second package thus permitting the machineto run continuously without stopping to change packages.

A yarn guide is included for each needle of the knitting head so thatyarn is moved under tension within the guide by a rotating member withminimal friction to a position where the needle will trap the yarn onits downward stroke.

This arrangement also permits a plurality of like knitting heads to bemounted in relatively close proximity in a single machine frame in sucha manner that chain stitches can be fed from a power driven warp beam.

In a preferred arrangement, a plurality of knitting heads are mounted ona knitting head frame fed from a single warp and stationary creels canbe mounted at the sides of the frame for supplying weft yarn torespective knitting heads. The knitting head frame can also include afabric take-off roll for receiving the knitted fabric from each of theknitting heads. In an alternative arrangement the knitting heads may bemounted on a frame fed by a plurality of warps.

Each knitting head consists of a hollow cylinder having a plurality ofgrooves called tricks, in the outer wall, in which needles are disposed.Fixed feeders are disposed above the cylinder to offer the warp yarns tothe needle. Disposed between the cylinder and the fixed feeder is arotating weft feeder and yarn deflector. Rotation of the feeder issynchronized with a cam which raises the needles so that the feederdeflects the warp yarn within the yarn guide and guides and lays theelastic weft yarn outside the needle so that as the needle rises andfalls the rubber yarn is trapped between the chain stitches and fallsbehind the needle as a stitch is made, in a spiral fashion to provideradial and circumferential elasticity or rigidity in the knitted fabric.

The fixed feeders are mounted radially in the supported feeder headsupport tube through which passes a tube mounted in bearings andcarrying the weft feeder and deflector so that these can be rotated by asynchronised drive while feeding the inlay weft thread. The fixedfeeders are wire staples which are shaped so that pre-tensioning of theyarn before it reaches the guide ensures that the yarn lies in front ofand to one side of the open hook of the needle, and limits yarn movementwhen contacted with the placer. The staple has a curved portion fordefining the path of the yarn as it is moved. The placer is a planarelement which has a curved portion which pushes the yarn along theinternal rim of the feeder from a first position to a second positionwhere the yarn is trapped.

Accordingly, in one aspect of the present invention there is provided aknitting head for use with a knitting machine said knitting headcomprising:

a fixed hollow cylinder having a cylinder wall with a plurality ofcircumferentially spaced grooves disposed in said wall, each groovehaving a needle with a hook at its upper end disposed therein,

said hollow cylinder being disposed in a cam box having rotary cam meansadapted to be coupled to each needle so that rotation of said rotary cammeans causes displacement of each needle along its respective groove,

stationary warp yarn delivery means disposed above said hollow cylinderfor feeding a warp yarn from a remote location to each respectiveneedle,

rotatable weft yarn delivery means disposed between said hollow cylinderand said stationary warp yarn delivery means for delivering a weft yarnfrom a remote location outside the cylinder and from the inside to theoutside of said rotatable weft delivery means so that the weft yarn islaid on the outside of each successively rising needle,

the speed of rotation of said rotary cam means and said rotatable weftyarn delivery means being synchronised whereby in use, upon rotation ofsaid rotary cam means and said rotatable weft yarn delivery meansdisplacement of said needles causes chain stitches to be made which arefed inside said cylinder, and said rotatable weft yarn delivery meansdelivers said weft yarn outside said needle as said needles rise and thetension in said weft yarn pulls it over the top of the needle when itdescends to be trapped in a subsequent stitch which falls behind theneedle as the stitch is made, said rotatable weft yarn delivery meanscomprising a generally planar horizontal weft yarn rotatable feeder anddeflector element, said rotatable feeder and deflector element beingcoupled to a rotatable hollow yarn delivery tube driven by drive means,said tube and said rotating feeder and deflector having passage meansthrough which a weft thread can be fed to be disposed outside theperiphery of the hollow cylinder, the deflector including an outer camportion for deflecting the warp yarn outside the periphery of the hollowcylinder as said deflector rotates.

Preferably, said needle includes a pivotable latch for preventing saidweft yarn from being hooked by said needle on a downward stroke.Conveniently, said grooves are disposed in an outer wall of said hollowcylinder and said needle hooks face outwardly.

Preferably also, the knitting head and needle grooves are generallyvertically disposed and the warp yarn is fed to said knitting head in agenerally vertical direction.

Conveniently, said rotatable weft yarn delivery means comprises agenerally planar horizontal weft yarn rotatable feeder and deflectorelement, said rotatable feeder and deflector element being coupled to arotatable hollow yarn delivery tube which is adapted to be driven bydrive means, said tube and said rotating feeder and deflector havingpassage means through which a weft thread can be fed to be disposedoutside the needles as they rise. Conveniently, the deflector includesan outer cam portion for deflecting the warp yarn outside the peripheryof the hollow cylinder as said deflector rotates.

Accordingly, in another aspect of the invention there is provided aknitting machine comprising:

warp yarn delivery means for delivering a plurality of warp yarns to atleast one knitting head, said knitting head being disposed in a knittinghead frame and the knitting head receiving a plurality of warp yarns,said knitting head frame having a plurality of weft yarn package holdersdisposed at a remote position from said knitting head, at least onepackage holder being adapted to supply said at least one knitting headwith weft yarn, and a fabric take-off roll disposed in said knittinghead frame for receiving knitted fabric from said knitting machine, saidrotating weft yarn delivery means comprising a generally planarhorizontal weft yarn rotatable feeder and deflector element, saidrotatable feeder and deflector element being coupled to a rotatablehollow yarn delivery tube driven by drive means, said tube and saidrotating feeder and deflector element having passage means through whicha weft thread can be fed to be disposed outside the knitting head, thedeflector element including an outer cam portion for deflecting the warpyarn outside the periphery of the knitting head as said deflectorelement rotates.

Conveniently, said knitting machine has a plurality of knitting headsand said warp is driven by warp drive rollers and said warp yarn is fedacross to said knitting head frame via a warp sheet. Conveniently also,yarn tensioning devices are provided for controlling the tension of eachyarn fed to respective knitting heads.

Alternatively said knitting machine has a single head and said warp yarnis fed to said single head from a creel having a plurality of packageholders.

Accordingly, in yet another aspect of the invention there is yetprovided a method of knitting a tubular fabric using the knitting headas defined above comprising the steps: feeding a plurality of warp yarnthreads to a knitting head; feeding at least one weft yarn inside saidknitting head from a remote location outside said knitting head; passingthe weft yarn from the inside to the outside of said knitting head anddisposing said weft initially around the periphery of said knitting headby a rotary movement outside said needles as they arise, andsynchronising the movement of needles with respect to the rotating weftyarn delivery means within said knitting head to cause the weft yarndisposed around the periphery of said knitting head to be trappedbetween successive stitches of said warp yarn and to fall behind theneedle as a stitch is made to create a tubular structure comprising thesteps of feeding a plurality of warp yarn threads to a knitting headincluding vertically moveable needles, said knitting head including aninside and an outside, feeding at least one weft yarn inside saidknitting head from a remote location outside the knitting head,delivering the weft yarn from the inside to the outside of said knittinghead by a rotatable weft yarn delivery means comprising a generallyplanar horizontal weft yarn rotatable feeder and deflector element, saidrotatable feeder and deflector element being coupled to a rotatablehollow yarn delivery tube driven by drive means, said tube and saidrotating feeder and deflector element having passage means through whicha weft thread is fed and disposing said weft yarn initially on theoutside of said knitting head by a rotary movement of an outer camportion of said deflector element to lay the weft yarn outside saidneedles as the needles rise, synchronizing movement and displacement ofneedles with respect to the delivery of the weft yarn to cause the weftyarn disposed around the outside of said knitting head to be trappedbetween successive stitches of said warp yarn and to fall behind theneedle as a stitch is made to create a tubular structure.

Conveniently, said method includes the step of feeding the warp and weftyarns from a remote stationary location. Preferably said warp yarns arefed vertically downwards to vertically disposed knitting heads.

Conveniently also, two weft package holders are provided for eachknitting head and the package holders are adapted to be tied together toprovide substantially continuous knitting by each knitting head toproduce a continuous tubular fabric.

According to yet another aspect of the present invention there isprovided warp yarn positioning apparatus when used in a high speedknitting apparatus comprising a knitting head having a plurality ofneedles, each of said needles being movable in a needle trick, said warpyarn positioning apparatus comprising a plurality of warp yarn guideseach guide defining an aperture for receiving a respective warp yarnpassing therethrough and for containing and controlling movement of eachof said warp yarns, each warp yarn guide being mounted above arespective needle, at least one yarn deflecting means being adapted torotate around said knitting head for engaging said warp yarn and fordeflecting said yarns across said apertures from a first position to asecond position such that, in said second position, each of said yarnsis trapped by its respective needle as it descends.

Preferably, said guide is a hardened wire staple.

Conveniently, each of said guides are mounted in a common place on ashallow, cylindrical stationary dial, said dial being disposed abovesaid knitting head.

Preferably also, said yarn deflecting means is a planar placing element,said planar placing element being movable around said knitting head andpassing above each of said guides. Alternatively, the placing elementcan pass beneath the shaped aperture.

Conveniently, a plurality of placing elements are mounted on an elongatemember connected to a cam box, said placing elements being associatedwith a cam of said cam box and said cam box being rotatable around saidstationary dial.

These and other aspect of the invention will become apparent from thefollowing description when taken in combination with the accompanyingdrawings in which:

FIG. 1 is a diagrammatic and perspective view of a knitting machineconsisting of a plurality of knitting heads in accordance with anembodiment of the invention;

FIG. 2 is a plan view of a knitting head of the knitting machine shownin FIG. 1;

FIG. 3 is a front elevation of the knitting head shown in FIG. 2;

FIG. 4 is an enlarged view of part of the knitting head shown in FIG. 2;

FIG. 5a, 5b are diagrammatic elevational views of the knitting headshowing the operation of the apparatus in accordance with the embodimentof the present invention;

FIG. 6 depicts part of a net knitted with a knitting head shown in FIGS.7, 8, and 9a-9g;

FIG. 7 is an enlarged said elevation of a knitting head in accordancewith an alternative embodiment of the invention;

FIG. 8 is a plan view taken on the lines 3—3 of FIG. 7 and depicting theshape of the weft yarn feeder and deflector, and

FIGS. 9a to g depict sequential stages in the knitting of a tubularfabric by the knitting head in accordance with the second embodiment ofthe present invention.

Reference is first made to FIG. 1 of the drawings which depicts a highspeed knitting machine generally indicated by reference numeral 10 inwhich warp yarn 12 is fed from a warp drum 14 driven by warp driverollers 16 across a generally horizontally warp sheet 20. Tensioned warpyarns are downwardly of each of a plurality of knitting head 22 disposedat the top of a knitting head frame 24. This involves guiding the yarnaround the needles to appropriate positions which facilitate knitting byyarn positioning apparatus as will be later described in detail. At theside of the knitting head frame 24 is disposed a plurality of weft yarnpackage holders 26 and the weft yarn 27 is also fed inside respectiveknitting heads on the frame. The tubular fabric is knitted, as will belater described in detail and the tubular fabric is supplied to fabrictake-off rolls 28 for storing the knitted tubular fabric.

It will be appreciated that there is a plurality of separate knittingheads disposed in relatively close proximity on a single knitting headframe and the weft yarn package holders 26 are disposed at the side ofthe frame and one pair of weft package holders can be used to supply asingle knitting head. Alternatively, a single package holder can be usedto supply a single knitting head.

It will be understood that an advantage of this arrangement is that thetail of one package can be tied onto the free end of the next creel toprovide substantially continuous knitting of the tubular fabric and alsothat the knitting heads are limited to a relatively small areaminimising the volume and weight requirements.

Reference is now made to FIGS. 2 and 3 of the drawings which show aknitting head 22 incorporating warp yarn positioning apparatus inaccordance with an embodiment of the present invention. The knittinghead 22 comprises a cylinder 34 mounted inside a rotatable cylindricalcam box 36. Spaced around the periphery of cylinder 34 are a pluralityof needle tricks 38. A needle 40 is mounted in each needle trick 38 andeach needle 40 is movable up and down the needle trick 38 by amechanism, not shown in the interest of clarity, to facilitate theknitting process. Rotatable weft yarn delivery means are disposedbetween the hollow cylinder 34 and the stationary warp yarn deliverymeans 20 for delivering a weft yarn 27 from a remote location outsidethe cylinder 34 from the inside to the outside of the rotatable weftyarn delivery means so that the weft yarn 27 is laid down outside eachsuccessively rising needle 40. An example of a suitable weft yarndelivery means is shown in FIG. 8.

Mounted above the cylinder 34 is a shallow cylindrical dial 42. The dial42 has disposed around the circumference of its outer wall a number ofyarn guides 44 in the form of hardened wire stapled which are easy toproduce and to locate on the dial 42. Each yarn guide 44 is disposedabove a needle trick 38 and defines with the dial wall, an aperture 45for receiving the yarn so that movement of the warp yarn 12 is guidedwithin the aperture 45 around the needle 40 as will be described.

Mounted on the rotatable cam box 36 is an upstanding elongate member 46.The member 46 lies adjacent to the cylinder 34 and dial 42. Mounted ontop of member 46 is a planar placing element or deflector 48 which has acurved edge portion 49 for engaging the yarn 12 as seen in FIG. 3.

The placing element 48 is rotatable around the dial 42 with the cam box36 as it rotates around the cylinder 34. The placing element thus passesabove each guide 44 and causes movement of the position of the yarn 12within the aperture 45 within the wire guide 44 as will be described.

Reference is now made to FIG. 4 of the drawings which is an enlargedview of part of the knitting head 32 showing one needle trick 38 andwire yarn guide 44. The yarn guide 44 is adjustable and is held in placeby fixing screw 55. The guide has a first straight wire portion 51, acurved portion 53 which returns to the dial wall. Yarn 12 is showntensioned and held to one side of the guide 44 where it is retained at afirst corner 50 of the guide 44 between the straight portion 51 andcurved portion 53. The curved edge portion 49 of the placing element 48lies intermediate portions 57 and 59 and is proportioned to move theyarn from the corner 50 around portion 53 of the guide 44 so that theyarn can be trapped by a needle 40 as will be later described.

In operation, as the cam box rotates in the direction A as shown, theplacing elements 48 passes above the yarn guide 44 and the portions 57engages the yarn 12 which is pushed around the internal rim of curvedportion 53 of the yarn guide 44 to a second corner 52, defined by theportion 53 and dial wall. The yarn is secured on the hook 56 of needle40 as best seen in FIGS. 5a and 5b before the trailing end 54 of theplacing element passes over the guide 44. The yarn 12 is trapped in thehook 56 until the trailing end 54 of the placing element 48 has passedover the guide 44.

Reference is now made to FIGS. 5a, 5b of the drawings which arediagrammatic side and front elevational views of the placing elementengaging the yarn during operation of the apparatus. FIGS. 5a and 5bshow that before placing element 48 passes over guide 44 the tensionedyarn 12 is positioned and retained in the first corner 50 of guide 44.

The yarn 12 passes down one side of the needle 40 in the raisedposition. As the placing element 48 rotates, the yarn, shown in brokenoutline, is pushed around the guide 44 to the second corner 52 best seenin FIG. 5b where it now lies across the raised needle 40. As describedabove, the yarn 12 will stay in this position until the placing element48 is no longer above the guide 44. Before the placing element 48 haspassed over guide 44 the needle 40 descends, the hook 56 traps the yarn12 and pulls the yarn down into the previous chain stitch of chainstitches 58. When the placing element is no longer above the guide 44the yarn will return to rest in first corner 50 of the guide 44 ready toreceive the next pass of the placing element. This procedure is repeatedfor each needle around the periphery of the dial as the placing element48 rotates with the cam box 32.

Reference is now made to FIG. 7 of the drawings which depicts a knittinghead in accordance with an alternative embodiment of the presentinvention, which is mounted on a knitting frame in the same manner asthe knitting heads 22 as shown in FIG. 1. Each knitting head 32 consistsof a vertically disposed hollow cylinder 60 which in turn is mounted ina cam box 62. The cylinder 60 is fixed and on its exterior periphery aplurality of vertical grooves 64 are disposed spaced equidistantlyaround the circumference of the cylinder 60. As will be later describedin detail, the grooves, or “tricks”, as they are known in the art andeach contain a single needle 66 for performing the knitting operation.Disposed above the cylinder 60 are the warp and weft yarn feeding means.The warp yarn feeding means is provided via a plurality of radiallydisposed feeding elements 68 of which two are shown in detail. Each warpfeeding element consists of a generally horizontal bar having anaperture 69 therein through which the warp yarn passes to be gathered bythe needle 66 as will be described. The warp yarn feeding elements 68are stationary and are secured to the knitting frame.

As best seen in FIGS. 7 and 8 the weft yarn feeding means consists oftwo parts, the first part is a generally vertically disposed tube 70which is mounted on bearings 72 within a tube support 74. The tube 70 isrotatable by a timing pulley 76 coupled to a timing drive belt 78 andcoupled to the bottom of the tube 70 is a generally planar weft yarnfeeder and warp yarn deflector generally indicated by reference numeral80. The deflector has a channel 82 therein which communicates with theinterior 71 of the tube 70 through which the weft yarn 27 can be fed tothe tail 84 of the feeder and thence to the knitting head. It will beappreciated that the deflector 80 has an arcuate portion 86, parts ofwhich extends beyond the outer radius of the cylinder 60, and this isfor deflecting the warp yarn sideways beyond the periphery of thecylinder 60 during the knitting process to lay down the weft yarn 27 ina spiral fashion as will be described. It will be appreciated that thetiming belt and timing pulley cause the tubular portion 70 and deflector82 to rotate simultaneously and this rotation is synchronised with therotation of the cam box which causes the needles to be displacedvertically upwards and downwards within the respective grooves as willbe described.

Reference is now made to FIGS. 9a through g of the drawings whichdepicts the operation of a single needle to knit part of a tubularfabric. It will be appreciated that the other needles in the knittinghead operate in an identical manner. FIG. 9a depicts a warp yarn 12 fedthrough the aperture 69 of the stationary warp feeder element 68 to theneedle 66 and then to the fabric 88 consisting of a chain stitch. Inthis figure the needle is shown totally within the groove 64. It will beseen that the needle carries a pivotable latch 90 for preventinginadvertent hooking of the elastic weft yarn as will be described.

Reference is now made to FIG. 9b which shows the needle 66 rising afterthe passage of the deflecting element 82 which causes the warp yarn 12to be deflected outwards away from the needle 66 and simultaneously theweft yarn is laid on the open side or outside of the needle hook 67.After the passage of the deflecting element 82 the needle 66 risesfurther leaving the weft yarn 27 on the open latch 90 and permitting thewarp yarn 12 to return to its original position.

As the needle continues to rise as best seen in FIG. 9d the latch 90slips from beneath the thread 27 and pivots upwardly to its unrestrainedposition but is prevented from closing the needle hook 69 by a latchstop 92 disposed on the element 68. It will also be seen in FIG. 9e thatthe latch 90 has returned to a downwardly oriented position. The warpthread 27 remains outside the needle 66 and lies under the open latch90. As the needle descends as shown in FIG. 9f the latch is closed bythe old stitch and the weft yarn 27 thus preventing the weft yarn 27from being snagged in the hook 67.

When the needle has been retracted into the groove 64 the tension in theweft yarn 27 pulls it over the top of the needle 67 so that it fallsbehind the needle towards the centre of the cylinder, and on the nextascent of the needle for the next stitch, the weft yarn is trappedbetween successive stitches. When this is repeated for each needle inthe knitting head a tubular fabric results which consists of a pluralityof vertically disposed chain stitches coupled by a spirally wound weftyarn which is made of an elastic fabric. Depending on the number of camsfitted in the cam box the needle will continue to knit plain chainstitches until the next circuit of the feeder.

As the tubular fabric is knitted it is fed out as aforedescribed to thefabric take-off roll 28.

Reference is now made to FIG. 6 of the drawings which depicts part of anet fabric knitted with the knitting head shown in FIGS. 7, 8, 9a-9g. Itwill be seen that the yarns 12 cross the elasticated weft yarn 27 whichis spirally wound obliquely. If an end of warp yarn thread is pulled thethread unravels clear of the fabric.

Several modifications can be made to the first embodiment hereinbeforedescribed without departing from the scope of the invention. The wireguide and curved surface of placing element could be of any suitableshape as long as their engagement causes the yarn to be placed acrossthe needle in such a position that it is trapped in the hook on thedescent. The placing elements could also pass beneath the shapedaperture to move the yarn. Any suitable number of placing elements couldbe mounted around the cam box, one element per cam, as required toincrease the number of stitches between inlays. Any number of needletricks can be mounted around the cylinder with each needle trick havinga corresponding yarn guide disposed above the trick on the dial. Theyarn guide needs only to define an approximately horizontal shapedaperture to control the movement of the yarn. It will be understood thatthe yarn positioning apparatus may be used with a single head circularknitting machine fed from a creel as well as with a multiple headcircular knitting machine fed from a beam.

This involves guiding the yarn around the needles to appropriatepositions which facilitate knitting by yarn positioning apparatus aswill be later described in detail.

It will be appreciated that modifications may also be made to the secondembodiment hereinbefore described without departing from the scope ofthe invention. For example, it will be understood that the number ofneedles and the type of stitching may be varied as required to knitdifferent tubular fabrics. In addition, it will be appreciated that theweft or warp threads could be doubled to provide a heavier stitch andthe rotation rate of the deflector and rotary cam box drive can bevaried although it has to be synchronized to permit a satisfactoryknitting operation. It will also be appreciated that other means may beused to prevent the hook 67 from snagging on the yarn during thedownward stroke although the present arrangement is straightforward andelegant in its simplicity. It will also be appreciated that the warp andweft yarns may be made of elastic or non-elastic materials although thewarp yarn is generally non-elastic and the weft yarn is elastic. Also,two or more packages may be used to supply a single knitting head andthis number can be varied. It will be appreciated that the knittingheads could be disposed in a non-vertical orientation, for example,horizontally and, if so the warp yarns also fed to the knitting headshorizontally.

As with the first embodiment it will be understood that a singleknitting head could be used which is fed from a creel containing two ormore packages instead of a beam or frame.

Advantages of the invention are that high speed knitting of a tubularfabric can be achieved in a simple and efficient manner. The knittingcan be made continuous by simply tying the end of one package to thebeginning of another package and this avoids the necessity for stoppingand reloading the machine every time the package runs empty with theresults that retensioning or resetting is also avoided. A plurality ofknitting heads can be disposed in a single frame in proximity to eachother to minimise the space requirements and to facilitate inspection ofthe machine and also production of the tubular fabric.

The yarn positioning apparatus is relatively inexpensive and uses aminimal number of moving parts. The yarn is positioned across the needleas it is tensioned minimising wear and tear of the knitting elements andyarn. Splitting of the yarn and the dropping of stitches is minimised.High yarn tensions are possible and hence the apparatus can be used withhigh speed knitting machines.

I claim:
 1. A knitting head for use with a knitting machine, saidknitting head comprising: a fixed hollow cylinder wall having an insideand an outside and with a plurality of circumferentially spaced groovesdisposed in said wall, each groove having a needle with a hook at anupper end disposed therein, said hollow cylinder being disposed in a cambox having rotary cam means coupled to each needle so that rotation ofsaid rotary cam means causes displacement of each needle along itsrespective groove, stationary warp yarn delivery means disposed abovesaid hollow cylinder for feeding a warp yarn from a remote location toeach respective needle for being knitted into a warp chain, rotatableweft yarn delivery means disposed between said hollow cylinder and saidstationary warp yarn delivery means and including a weft yarn guideextending from the inside of the cylinder wall to the outside of thewall for delivering a weft yarn from the inside to the outside of saidcylinder wall to lay the weft yarn externally of each needle so that theweft yarn is trapped by the knitted warp chains without being knititself, said rotary cam means and said rotatable weft yarn deliverymeans being rotated in synchronization whereby, in use, upon rotation ofsaid rotary cam means and said rotatable weft yarn delivery meansdisplacement of said needles causes chain stitches to be made which arefed inside said cylinder, and said rotatable weft yarn delivery meansdelivers said weft yarn outside said needles as said needles rise andthe tension in said weft yarn pulls the weft yarn over the top of theneedle when the needle descends to trap the weft yarn in a subsequentstitch which falls behind the needle as the stitch is made.
 2. Aknitting head as claimed in claim 1 wherein each said needle includes apivotable latch for preventing said weft yarn from being hooked by saidneedle on a downward stroke.
 3. A knitting head as claimed in claim 1wherein said stationary warp yarn delivery means comprises a pluralityof stationary warp yarn delivery elements, a respective element beingassociated with a respective needle and being vertically disposed abovesaid needle but being slightly offset therefrom to permit said needle tolie vertically above said element to collect a length of thread as itdescends.
 4. A knitting head as claimed in claim 3 wherein said elementis in the form of a generally horizontal bar having an aperture thereinthrough which said warp yarn is passed.
 5. A knitting head as claimed inclaim 4for use with a knitting machine, said knitting head comprising: afixed hollow cylinder wall having an inside and an outside and with aplurality of circumferentially spaced grooves disposed in said wall,each groove having a needle with a hook at an upper end disposedtherein, said hollow cylinder being disposed in a cam box having rotarycam means coupled to each needle so that rotation of said rotary cammeans causes displacement of each needle along its respective groove,stationary warp yarn delivery means disposed above said hollow cylinderfor feeding a warp yarn from a remote location to each respective needlefor being knitted into a warp chain, rotatable weft yarn delivery meansdisposed between said hollow cylinder and said stationary warp yarndelivery means and including a weft yarn guide extending from the insideof the cylinder wall to the outside of the wall for delivering a weftyarn from the inside to the outside of said cylinder wall to lay theweft yarn externally of each needle so that the weft yarn is trapped bythe knitted warp chains without being knit itself, said rotary cam meansand said rotatable weft yarn delivery means being rotated insynchronization whereby, in use, upon rotation of said rotary cam meansand said rotatable weft yarn delivery means displacement of said needlescauses chain stitches to be made which are fed inside said cylinder, andsaid rotatable weft yarn delivery means delivers said weft yarn outsidesaid needles as said needles rise and the tension in said weft yarnpulls the weft yarn over the top of the needle when the needle descendsto trap the weft yarn in a subsequent stitch which falls behind theneedle as the stitch is made, wherein said stationary warp yarn deliverymeans comprises a plurality of stationary warp yarn delivery elements, arespective element being associated with a respective needle and beingvertically disposed above said needle but being slightly offsettherefrom to permit said needle to lie vertically above said element tocollect a length of thread as it descends, and wherein said element isin the form of a generally horizontal bar having an aperture thereinthrough which said warp yarn is passed, and wherein each elementincludes a latch stop for restricting the upward pivotable movement ofeach latch on said needle.
 6. A knitting head as claimed in claim 1foruse with a knitting machine, said knitting head comprising: a fixedhollow cylinder wall having an inside and an outside and with aplurality of circumferentially spaced grooves disposed in said wall,each groove having a needle with a hook at an upper end disposedtherein, said hollow cylinder being disposed in a cam box having rotarycam means coupled to each needle so that rotation of said rotary cammeans causes displacement of each needle along its respective groove,stationary warp yarn delivery means disposed above said hollow cylinderfor feeding a warp yarn from a remote location to each respective needlefor being knitted into a warp chain, rotatable weft yarn delivery meansdisposed between said hollow cylinder and said stationary warp yarndelivery means and including a weft yarn guide extending from the insideof the cylinder wall to the outside of the wall for delivering a weftyarn from the inside to the outside of said cylinder wall to lay theweft yarn externally of each needle so that the weft yarn is trapped bythe knitted warp chains without being knit itself, said rotary cam meansand said rotatable weft yarn delivery means being rotated insynchronization whereby, in use, upon rotation of said rotary cam meansand said rotatable weft yarn delivery means displacement of said needlescauses chain stitches to be made which are fed inside said cylinder, andsaid rotatable weft yarn delivery means delivers said weft yarn outsidesaid needles as said needles rise and the tension in said weft yarnpulls the weft yarn over the top of the needle when the needle descendsto trap the weft yarn in a subsequent stitch which falls behind theneedle as the stitch is made, and wherein said rotatable weft yarndelivery means comprises a generally planar horizontal weft yarnrotatable feeder and deflector element, said rotatable feeder anddeflector element being coupled to a rotatable hollow yarn delivery tubedriven by drive means, said tube and said rotating feeder and deflectorhaving passage means through which a weft thread can be fed to bedisposed outside the periphery of the hollow cylinder.
 7. A knittinghead as claimed in claim 6 wherein the deflector includes an outer camportion for deflecting the warp yarn outside the periphery of the hollowcylinder as said deflector rotates.
 8. A knitting head as claimed inclaim 6 wherein said tubular yarn delivery tube is rotatable via bearingmeans in a support tube fixed and coupled to said stationary warpdelivery means.
 9. A knitting machine comprising: warp yarn deliverymeans for delivering a plurality of warp yarns to at least one knittinghead, said knitting head being disposed in a knitting head frame and theknitting head receiving a plurality of warp yarns for knitting the warpyarns into distinct warp chains without being knit itself, and havingrotating weft yarn delivery means substantially disposed within theknitting head for delivering a weft yarn to be trapped by the knittedwarp chains, said knitting head frame having a plurality of stationaryweft yarn package holders disposed at a remote position from saidknitting head and frame and for supplying said at least one knittinghead with weft yarn, and fabric take-off roll disposed in said knittinghead frame for receiving knitted fabric from said knitting machine. 10.A knitting machine as claimed in claim 9 wherein said knitting machinehas a plurality of knitting heads and said warp is driven by warp driverollers and said warp yarn is fed across to said knitting head frame viaa warp sheet.
 11. A knitting machine as claimed in claim 9or claim 10wherein yarn tensioning devices are provided from for controlling thetension of each yarn fed to respective knitting heads.
 12. A knittingmachine as claimed in claim 9 wherein said knitting machine has a singlehead and said warp yarn is fed to said single head from a creel having aplurality of package holders.
 13. A method of knitting a tubular fabriccomprising the steps of: feeding a plurality of warp yarn threads to aknitting head including vertically moveable needles so as to knit thewarp yarn threads into chains, said knitting head including an insideand an outside, feeding at least one weft yarn inside said knitting headfrom a remote location outside the knitting head; delivering the weftyarn from the inside to the outside of said knitting head so that theweft yarn is trapped by the knitted warp chains without being knit, anddisposing said weft yarn initially on the outside of said knitting headby a rotary movement of an outer cam portion of a deflector element tolay the weft yarn outside said needles as the needles rise,synchronizing movement and displacement of needles with respect to thedelivery of the weft yarn to cause the weft yarn disposed around theoutside of said knitting head to be trapped between successive stitchesof said warp yarn and to fall behind the needle as a stitch is made tocreate a tubular structure.
 14. A method as claimed in claim 13 whereinsaid method includes the step of feeding said warp yarn threads and saidat least one weft yarn from a remote stationary location.
 15. A methodas claimed in claim 13 or claim 14 wherein said warp yarns are fedvertically downwards to vertically disposed knitting heads.
 16. A methodas claimed in claim 13 wherein the delivery of the weft yarn and themovement and displacement of the needles in the knitting head issynchronized.
 17. A method as claimed in claim 13 wherein the remotelocation comprises two stationary package holders for each knitting headand yarn packages held on the package holders are tied together toprovide substantially continuous knitting by each knitting head toproduce a continuous tubular fabric.
 18. A knitting head as claimed inclaim 1, further including for use with a knitting machine, saidknitting head comprising: a fixed hollow cylinder wall having an insideand an outside and with a plurality of circumferentially spaced groovesdisposed in said wall, each groove having a needle with a hook at anupper end disposed therein, said hollow cylinder being disposed in a cambox having rotary cam means coupled to each needle so that rotation ofsaid rotary cam means causes displacement of each needle along itsrespective groove, stationary warp yarn delivery means disposed abovesaid hollow cylinder for feeding a warp yarn from a remote location toeach respective needle for being knitted into a warp chain, rotatableweft yarn delivery means disposed between said hollow cylinder and saidstationary warp yarn delivery means and including a weft yarn guideextending from the inside of the cylinder wall to the outside of thewall for delivering a weft yarn from the inside to the outside of saidcylinder wall to lay the weft yarn externally of each needle so that theweft yarn is trapped by the knitted warp chains without being knititself, said rotary cam means and said rotatable weft yarn deliverymeans being rotated in synchronization whereby, in use, upon rotation ofsaid rotary cam means and said rotatable weft yarn delivery meansdisplacement of said needles causes chain stitches to be made which arefed inside said cylinder, and said rotatable weft yarn delivery meansdelivers said weft yarn outside said needles as said needles rise andthe tension in said weft yarn pulls the weft yarn over the top of theneedle when the needle descends to trap the weft yarn in a subsequentstitch which falls behind the needle as the stitch is made, and a warpyarn positioning apparatus used in a high speed knitting apparatus,comprising a knitting head having a plurality of needles, each of saidneedles being movable in a needle trick, said warp yarn positioningapparatus comprising a plurality of warp yarn guides, each guidedefining an aperture for receiving a respective warp yarn passingtherethrough and for containing and controlling movement of each of saidwarp yarns, each warp yarn guide being mounted above a respectiveneedle, at least one yarn deflecting means for rotating being adapted torotate around said knitting head for engaging said warp yarns and fordeflecting said yarns across said aperture from a first position to asecond position such that, in said second position, each of said yarnsis trapped by a its respective needle as the needle it descends. 19.Yarn positioning apparatus as claimed in claim 18, wherein each yarnguide is a hardened wire staple.
 20. Yarn positioning apparatus asclaimed in claim 18 or claim 19 wherein each of said yarn guides aremounted in a plane on a shallow cylindrical stationary dial, said dialbeing disposed above said knitting head.
 21. Yarn positioning apparatusas claimed in claim 18 wherein said yarn deflecting means is a planarplacing element, said planar placing element being movable around saidknitting head and passing above each of said apertures.
 22. Yarnpositioning apparatus as claimed in claim 21 wherein a plurality ofplacing elements are mounted on an elongate member connected to a cambox, said placing elements being associated with a cam of said cam boxand said cam box being rotatable around said stationary dial.
 23. Yarnpositioning apparatus as claimed in claim 18, wherein said yarndeflecting means is by a planar placing element, said placing elementbeing movable around said knitting head and passing beneath the yarnguides.
 24. A knitting head for use with a knitting machine, saidknitting head comprising: a fixed hollow cylinder wall having an insideand an outside and with a plurality of circumferentially spaced groovesdisposed in said wall, each groove having a needle with a hook at anupper end disposed therein, said hollow cylinder being disposed in a cambox having a rotary cam means coupled to each needle so that rotation ofsaid rotary cam means causes displacement of each needle along itsrespective groove, stationary warp yarn delivery means disposed abovesaid hollow cylinder for feeding a warp yarn from a remote location toeach respective needle, rotatable weft yarn delivery means disposedbetween said hollow cylinder and said stationary warp yarn deliverymeans and including a weft yarn guide extending from the inside of thecylinder wall to the outside of the wall for delivering a weft yarn fromthe inside to the outside of said cylinder wall to lay the weft yarnexternally of each needle, said rotary cam means and said rotatable weftyarn delivery means being rotated in synchronization whereby, in use,upon rotation of said rotary cam means and said rotatable weft yarndelivery means displacement of said needles causes chain stitches to bemade which are fed inside said cylinder, and said rotatable weft yarndelivery means delivers said weft yarn outside said needles as saidneedles rise and the tension in said weft yarn pulls the weft yarn overthe top of the needle when the needle descends to trap the weft yarn ina subsequent stitch which falls behind the needle as the stitch is made,said rotatable weft yarn delivery means comprising a generally planarhorizontal weft yarn rotatable feeder and deflector element, saidrotatable feeder and deflector element being coupled to a rotatablehollow yarn delivery tube driven by drive means, said tube and saidrotating feeder and deflector having passage means through which a weftthread can be fed to be disposed outside the periphery of the hollowcylinder, the deflector including an outer cam portion for deflectingthe warp yarn outside the periphery of the hollow cylinder as saiddeflector rotates.
 25. A knitting head as claimed in claim 24 whereineach said needle includes a pivotable latch for preventing said weftyarn from being hooked by said needle on a downward stroke.
 26. Aknitting head as claimed in claim 24 wherein said stationary warp yarndelivery means comprises a plurality of stationary warp yarn deliveryelements, a respective element being associated with a respective needleand being vertically disposed above said needle but being slightlyoffset therefrom to permit said needle to lie vertically above saidelement to collect a length of thread as it descends.
 27. A knittinghead as claimed in claim 26 wherein said element is in the form of agenerally horizontal bar having an aperture therein through which saidwarp yarn is passed.
 28. A knitting head as claimed in claim 27 whereineach element includes a latch stop for restricting the upward pivotablemovement of each latch on said needle.
 29. A knitting head as claimed inclaim 24 wherein said rotatable weft yarn delivery means comprises agenerally planar horizontal weft yarn rotatable feeder and deflectorelement, said rotatable feeder and deflector element being coupled to arotatable hollow yarn delivery tube driven by drive means, said tube andsaid rotating feeder and deflector having passage means through which aweft thread can be fed to be disposed outside the periphery of thehollow cylinder.
 30. A knitting head as claimed in claim 29 wherein thedeflector includes an outer cam portion for deflecting the warp yarnoutside the periphery of the hollow cylinder as said deflector rotates.31. A knitting head as claimed in claim 24 wherein said tubular yarndelivery tube is rotatable via bearing means in a support tube fixed andcoupled to said stationary warp delivery means.
 32. A knitting machinecomprising: warp yarn delivery means for delivery a plurality of warpyarns to at least one knitting head, said knitting head being disposedin a knitting head frame and the knitting head receiving a plurality ofwarp yarns and having rotating weft yarn delivery means substantiallydisposed within the knitting head, said knitting head frame having aplurality of stationary weft yarn package holders disposed at a remoteposition from said knitting head and frame and for supplying said atleast one knitting head with weft yarn, and fabric take-off rolldisposed in said knitting head frame for receiving knitted fabric fromsaid knitting machine, said rotating weft yarn delivery means comprisinga generally planar horizontal weft yarn rotatable feeder and deflectorelement, said rotatable feeder and deflector element being coupled to arotatable hollow yarn delivery tube driven by drive means, said tube andsaid rotating feeder and deflector element having passage means throughwhich a weft thread can be fed to be disposed outside the knitting head,the deflector element including an outer cam portion for deflecting thewarp yarn outside the periphery of the knitting head as said deflectorelement rotates.
 33. A knitting machine as claimed in claim 32 whereinsaid knitting machine has a plurality of knitting heads and said warp isdriven by warp drive rollers and said warp yarn is fed across to saidknitting head frame via a warp sheet.
 34. A knitting machine as claimedin claim 32 or claim 33 wherein yarn tensioning devices are providedfrom controlling the tension of each yarn fed to respective knittingheads.
 35. A knitting machine as claimed in claim 32 wherein saidknitting machine has a single head an said warp yarn is fed to saidsingle head from a creel having a plurality of package holders.
 36. Amethod of knitting a tubular fabric comprising the steps of: feeding aplurality of warp yarns threads to a knitting head including verticallymoveable needles, said knitting head including an inside and an outside,feeding at least one weft yarn inside said knitting head from a remotelocation outside the knitting head; delivering the weft yarn from theinside to the outside of said knitting head by a rotatable weft yarndelivery means comprising a generally planar horizontal weft yarnrotatable feeder and deflector element, said rotatable feeder anddeflector element being coupled to a rotatable hollow yarn delivery tubedriven by drive means, said tube and said rotating feeder and deflectorelement having passage means through which a weft thread is fed anddisposing said weft yarn initially on the outside of said knitting headby a rotary movement of an outer cam portion of said deflector elementto lay the weft yarn outside said needles as the needles rise,synchronizing movement and displacement of needles with respect to thedelivery of the weft yarn to cause the weft yarn disposed around theoutside of said knitting head to be trapped between successive stitchesof said warp yarn and to fall behind the needle as a stitch is made tocreate a tubular structure.
 37. A method as claimed in claim 36 whereinsaid method includes the step of feeding said warp yarn threads and saidat least one weft yarn from a remote stationary location.
 38. A methodas claimed in claim 36 or claim 37 wherein said warp yarns are fedvertically downwards to vertically disposed knitting heads.
 39. A methodas claimed in claim 36 wherein the delivery of the weft yarn and themovement and displacement of the needles in the knitting head issynchronized.
 40. A method as claimed in claim 36 wherein the remotelocation comprises two stationary package holders for each knitting headand yarn packages held on the package holders are tied together toprovide substantially continuous knitting by each knitting head toproduce a continuous tubular fabric.
 41. A knitting machine comprising:warp yarn delivery means for delivering a plurality of warp yarns to atleast one knitting head, said knitting head being disposed in a knittinghead frame and the knitting head receiving a plurality of warp yarns forknitting the warp yarns into distinct warp chains without being knititself, and having rotating weft yarn delivery means substantiallydisposed within the knitting head for delivery a weft yarn to be trappedby the knitted warp chains, said knitting head frame having a pluralityof stationary weft yarn package holders disposed at a remote positionfrom said knitting head and frame and for supplying said at least oneknitting head with weft yarn, and fabric take-off roll disposed in saidknitting head frame for receiving knitted fabric from said knittingmachine, wherein said knitting machine has a plurality of knitting headsand said warp is driven by warp drive rollers and said warp yarn is fedacross to said knitting head frame via a warp sheet, and wherein yarntensioning devices are provided for controlling the tension of each yarnfed to respective knitting heads.
 42. A method of knitting a tubularfabric comprising the steps of: feeding a plurality of warp yarn threadsto a knitting head including vertically moveable needles so as to knitthe warp yarn threads into chains, said knitting head including aninside and an outside, feeding at least one weft yarn inside saidknitting head from a remote location outside the knitting head;delivering the weft yarn from the inside to the outside of said knittinghead so that the weft yarn is trapped by the knitted warp chains withoutbeing knit, and disposing said weft yarn initially on the outside ofsaid knitting head by a rotary movement to lay the weft yarn outsidesaid needles as the needles rise, synchronizing movement anddisplacement of needles with respect to the delivery to the weft yarn tocause the weft yarn disposed around the outside of said knitting head tobe trapped between successive stitches of said warp yarn and to fallbehind the needle as a stitch is made to create a tubular structure.